JP5878429B2 - Magnesium fluoride particles, method for producing magnesium fluoride particles, magnesium fluoride particle dispersion, method for producing magnesium fluoride particle dispersion, composition for forming low refractive index layer, method for producing composition for forming low refractive index layer , Substrate with low refractive index layer and method for producing substrate with low refractive index layer - Google Patents

Description

  The present invention relates to magnesium fluoride particles, a method for producing magnesium fluoride particles, a magnesium fluoride particle dispersion, a method for producing a magnesium fluoride particle dispersion, a composition for forming a low refractive index layer, and a composition for forming a low refractive index layer. The present invention relates to a manufacturing method of a product, a substrate with a low refractive index layer, and a method of manufacturing a substrate with a low refractive index layer.

  The display market is expanding with the development of flat panel displays such as liquid crystal displays (LCDs) and plasma display panels (PDPs), and the development of high-performance displays aimed at high-definition, high-gradation and high-contrast displays is underway. It has been broken. With the development of higher performance, the application of an antireflection layer to the display surface is becoming widespread. The antireflection layer includes a high refractive index layer and a low refractive index layer, and utilizes the phase difference of light reflected on the surface of each material of the high refractive index layer and the low refractive index layer, thereby allowing external light on the display surface. Prevent reflection.

  The formation method of the low refractive index layer is roughly divided into a vapor phase method and a coating method. In particular, the coating method has good utilization efficiency of raw materials, and is superior to the vapor phase method in terms of mass production and equipment cost. Therefore, at present, a highly productive coating method is used for forming the low refractive index layer.

  In particular, it is known that magnesium fluoride sol and magnesium fluoride fine powder are effective as a microfiller for a low refractive layer coating agent (Patent Document 1, Patent Document 2). Further, as a method of forming the low refractive index layer, the coating film constituting the low refractive index layer is coated by including bubbles having a refractive index of 1 and a size equal to or less than the wavelength of visible light. A method for reducing the refractive index of the entire film is known. For example, hollow fine particles such as hollow silica are contained in the coating film (Patent Documents 3 and 4).

JP 63-124332 A JP-A-2-26824 Japanese Patent Laid-Open No. 2001-167637 JP 2002-265866 A

  In Patent Document 1 and Patent Document 2, it is necessary to improve the dispersibility of magnesium fluoride in order to obtain transparency. If the primary particle diameter is reduced, productivity is lowered. In Patent Document 3 and Patent Document 4, it is possible to form a hard coating film by using hollow silica particles, but mechanical strength and scratch resistance are inferior.

  The present invention has been made in view of the above problems, and has a low refractive index and excellent film forming properties, magnesium fluoride particles, a method for producing magnesium fluoride particles, a magnesium fluoride particle dispersion, and a magnesium fluoride particle dispersion. It is an object of the present invention to provide a production method of the present invention, a composition for forming a low refractive index layer, a method for producing a composition for forming a low refractive index layer, a substrate with a low refractive index layer, and a method for producing a substrate with a low refractive index layer. To do.

  In order to achieve the above object, the magnesium fluoride particles according to the present invention are magnesium fluoride particles containing at least one magnesium fluoride fine particle, and each of the at least one magnesium fluoride fine particle comprises a supported body. It has pores to carry.

  The at least one magnesium fluoride fine particle is a plurality of fine particles, and between the fine particles adjacent to each other among the plurality of fine particles, there are intergranular void-like pores that are gaps for supporting the supported member. obtain.

  The pores carry the supported body, and the supported body may be a substance used in the process of generating the at least one magnesium fluoride fine particle.

  The pores carry the supported body, and the supported body may have a lower refractive index than the at least one magnesium fluoride fine particle.

  The support may be at least one of a gas containing an inert gas or a liquid containing an organic solution.

  The fine pores are fine pores that are open in the state of being opened on the surface of the magnesium fluoride fine particles, and fine particles that are in the state of being blocked from the surface of the magnesium fluoride fine particles inside the magnesium fluoride fine particles. It may be at least one of an inner closed pore.

  The grain boundary void-like pore may be at least one of a grain boundary void-like open pore that exists in an open state and a grain boundary void-like closed pore that exists in a closed state.

  The magnesium fluoride fine particles may have an average particle size of 1 nm to 100 nm.

  The magnesium fluoride fine particles may have an average particle size of 1 nm to 50 nm.

  The magnesium fluoride fine particles may have a refractive index in the range of 1.20 to 1.40.

The specific surface area of the magnesium fluoride fine particles by BET method may be in the range of 150 m ² / g to 300 m ² / g.

  In order to achieve the above object, a magnesium fluoride particle dispersion according to the present invention includes the magnesium fluoride particles described above and a dispersion medium in which the magnesium fluoride particles are dispersed.

  The dispersion medium may include a dispersant that promotes dispersion of the magnesium fluoride particles.

  In order to achieve the above object, a composition for forming a low refractive index layer according to the present invention comprises the magnesium fluoride particles described above and a layer forming material in which the magnesium fluoride particles are dispersed.

  In order to achieve the above object, a base material with a low refractive index layer according to the present invention includes a resin substrate, a hard coat layer formed on the resin substrate, and a low refractive index formed on the hard coat layer. It is a base material with a low refractive index layer containing a refractive index layer, Comprising: The said low refractive index layer is comprised from the composition for low refractive index layer formation as described above.

  In order to achieve the above object, a method for producing magnesium fluoride particles according to the present invention is a method for producing magnesium fluoride particles for producing magnesium fluoride particles containing at least one magnesium fluoride fine particle, wherein A preparation step of preparing a crystal, and a crystal generation step of generating a magnesium fluoride crystal having pores for supporting a supported body by discharging gas from the magnesium silicofluoride crystal by heat-treating the magnesium silicofluoride crystal. And a fine particle production step of producing the fine magnesium fluoride particles having the pores from the magnesium fluoride crystal.

  The at least one magnesium fluoride fine particle is a plurality of fine particles, and the crystal generation step is performed such that the interstitial voids are formed between the adjacent fine particles among the plurality of fine particles. It includes an agglomeration step of aggregating adjacent fine particles, and the intergranular void-like pores may be gaps that carry the support.

  The crystal generation step includes a step of forming open pores in the fine particles existing in an open state on the surface of the magnesium fluoride fine particles, and a blockage from the surface of the magnesium fluoride fine particles inside the magnesium fluoride fine particles. At least one of the steps of forming closed pores in the fine particles existing in a state.

  The agglomeration step includes at least one of a step of forming intergranular void-like open pores that exist in an open state and a step of forming intergranular void-like closed pores that exist in a closed state. obtain.

  The preparation step includes generating a magnesium silicofluoride particle aggregate slurry from a mixed solution of a magnesium salt and a solution containing silicofluoride ions, and generating a magnesium fluorosilicate particle paste from the magnesium silicofluoride particle aggregate slurry. A step of generating magnesium silicofluoride particles from the magnesium silicofluoride particle paste, a step of pulverizing the magnesium silicofluoride particles to generate a slurry of magnesium silicofluoride particles, and a slurry of the magnesium silicofluoride particles Forming the magnesium silicofluoride crystal from.

  In order to achieve the above object, a method for producing a magnesium fluoride particle dispersion according to the present invention includes a step of preparing the magnesium fluoride particles described above, and a dispersion step of dispersing the magnesium fluoride particles in a dispersion medium. Is included.

  The dispersion medium may include a dispersant that promotes dispersion of the magnesium fluoride particles.

  In order to achieve the above object, a method for producing a composition for forming a low refractive index layer according to the present invention comprises the steps of preparing the magnesium fluoride particles described above, and dispersing the magnesium fluoride particles in a layer forming material. A dispersion step.

  In order to achieve the above object, a method for producing a substrate with a low refractive index layer according to the present invention includes a step of preparing a resin substrate, a step of forming a hard coat layer on the resin substrate, and the hard coat layer. Forming a low refractive index layer on the substrate, wherein the low refractive index layer is formed from the composition for forming a low refractive index layer described above. It is configured.

The schematic diagram of the magnesium fluoride particle which concerns on embodiment of this invention is shown. The cross-sectional schematic diagram of the magnesium fluoride particle which concerns on embodiment of this invention is shown. 2 shows a transmission electron microscope (TEM) image of magnesium fluoride particles according to an embodiment of the present invention. It is a flowchart which shows the manufacturing method of the magnesium fluoride particle by embodiment of this invention. It is a schematic diagram which shows the magnesium fluoride particle dispersion liquid which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing method of the magnesium fluoride particle dispersion liquid by embodiment of this invention. It is a schematic diagram which shows the composition for low refractive index layer formation which concerns on embodiment of this invention. It is a flowchart which shows the manufacturing method of the composition for low refractive index layer formation by embodiment of this invention. It is a schematic diagram which shows the base material with a low refractive index layer by embodiment of this invention. It is a table | surface which shows the measurement result of the magnesium fluoride particle manufactured by running an Example and a comparative example, a low refractive index layer, and a base material with a low refractive index layer.

  Hereinafter, magnesium fluoride particles, a method for producing magnesium fluoride particles, a magnesium fluoride particle dispersion, a method for producing a magnesium fluoride particle dispersion, and a low refractive index layer forming method according to an embodiment of the present invention with reference to the drawings A composition, a method for producing a composition for forming a low refractive index layer, a substrate with a low refractive index layer, and a method for producing a substrate with a low refractive index layer will be described.

[Magnesium fluoride particles]
FIG. 1 shows a schematic diagram of magnesium fluoride particles 100 according to an embodiment of the present invention. The magnesium fluoride particle 100 includes at least one fine particle 110. The fine particles 110 are magnesium fluoride fine particles. The fine particles 110 have irregularities 120. A plurality of irregularities 120 of the fine particles 110 exist on the surface of the fine particles 110. The fine particles 110 have a plurality of pores 130 for supporting the support, and the fine particles 110 have a pore structure.

  The pores 130 may exist in an open state on the surface of the fine particles 110. Further, the pores 130 may exist even in a state where the pores 130 are blocked from the surface of the fine particles 110 inside the fine particles 110. When the magnesium fluoride particle 100 includes a plurality of fine particles 110, there is a gap for supporting the support between the fine particles 110 adjacent to each other among the plurality of fine particles 110, which form pores. The specific surface area of the magnesium fluoride particles 100 is preferably large, and the number of pores 130 is preferably large.

  The support to be carried by the pores 130 is a substance used in the process of generating the fine particles 110. For example, the supported body is at least one of a gas containing a gas (for example, an atmospheric gas such as an inert gas or air) or a liquid containing an organic solution, and one kind is carried by the pores 130 alone. Two or more kinds may be mixed and supported on the pores 130. For example, the supported body may have a lower refractive index than the fine particles 110.

  The average particle diameter of the magnesium fluoride particles 100 is in the range of 1 nm to 100 nm, preferably in the range of 1 nm to 50 nm, more preferably in the range of 1 nm to 30 nm. If the average particle diameter of the magnesium fluoride particles 100 is 1 nm or more and 50 nm or less, the magnesium fluoride particles 100 are easily dispersed in the low refractive index layer forming component, and the low refractive index layer (layer thickness 50 nm to 300 nm) or low It is suitable for forming a substrate with a refractive index layer. When the average particle size is 1 nm or more, the low refraction effect is not impaired, and the dispersion is stable. In addition, an average particle diameter is a particle diameter defined by 50 volume percent of the whole sample particle | grain consisting of particles below an average particle diameter (d50).

The specific surface area of the magnesium fluoride particles 100 is in the range of 150m ² / g~300m ² / g. When the specific surface area is in the range of 150m ² / g~300m ² / g, preferably the viewpoint of film forming ability is good. When the specific surface area is 150 m ² / g or more, the magnesium fluoride particles 100 are less likely to contain fine particles having no pores. Moreover, when the specific surface area is 300 m ² / g or less, the mechanical strength of the magnesium fluoride particles 100 can be kept at a certain level or more.

  The refractive index of the magnesium fluoride particles 100 is in the range of 1.20 to 1.40, preferably in the range of 1.20 to 1.36. When the refractive index of the magnesium fluoride particles 100 is in the range of 1.20 or more and 1.40 or less, the reflectance of the coating is preferably reduced. In particular, if the refractive index of the magnesium fluoride particles 100 is 1.20 or more, the strength of the magnesium fluoride particles 100 can be maintained. Moreover, if the refractive index of the magnesium fluoride particle 100 is 1.40 or less, the antireflective effect of the low refractive index layer containing the magnesium fluoride particle 100 and the substrate containing the low refractive index layer can be sufficiently obtained. it can.

  The refractive index of magnesium fluoride is usually in the range of 1.37 to 1.42, and the refractive index of the magnesium fluoride particles 100 is smaller. Based on this tendency, it can be seen that the structure of the magnesium fluoride particles 100 is a pore structure, and the magnesium fluoride particles 100 have pores 130. Note that the refractive index of the magnesium fluoride particles 100 can be controlled by the shape of the pores 130 and the substance (that is, solvent or gas) present in the pores 130. When the refractive index of the support supported by the pores 130 is lower than the refractive index of the fine particles 110, the refractive index of the magnesium fluoride particles 100 is lower than the refractive index of the fine particles 110.

  The refractive index of the low refractive index layer including the magnesium fluoride particles 100 is smaller than the refractive index of the low refractive index layer including the magnesium fluoride fine particles manufactured by another method different from the method according to the present invention. The refractive index of the low refractive index layer containing the magnesium fluoride particles 100 is smaller than the refractive index of the low refractive index layer containing fine particles (for example, silica fine particles) that are not magnesium fluoride fine particles.

  FIG. 2 is a schematic cross-sectional view of the magnesium fluoride particle 100 according to the embodiment of the present invention. With reference to FIG. 2, the variation of the pore 130 which the magnesium fluoride particle 100 has is demonstrated. The pore 130 is at least one of an intra-fine particle open pore 130a, an intra-fine particle closed pore 130b, a grain boundary void-like open pore 130c, and a grain boundary void-like closed pore 130d.

  The fine particle open pores 130 a are fine pores that are open on the surface of the fine particles 110. When a large number of open pores 130a in the fine particles are present in the fine particles 110, the fine particles 110 are porous. The intra-fine particle closed pores 130 b are pores that exist inside the fine particle 110 in a state of being blocked from the surface of the fine particle 110. In the fine particle closed pore 130 b, the surface portion of the fine particle 110 is closed and is isolated inside the fine particle 110. When many closed pores 130b in the fine particles exist in the fine particles 110, the fine particles 110 are partially hollow.

  When the magnesium fluoride particle 100 includes a plurality of fine particles 110, the magnesium fluoride particle 100 includes a gap for supporting a supported body between the adjacent fine particles 110, and the gap includes intergranular void-like pores. Eggplant. The grain boundary void-shaped pores include a grain boundary void-shaped open pore 130c and a grain boundary void-shaped closed pore 130d. The intergranular void-like open pores 130c are intergranular void-like pores that exist in an open state. The grain boundary void-shaped closed pores 130d are grain boundary void-shaped pores existing in a closed state. The intergranular void-like closed pores 130 d are closed at the surface portion of the magnesium fluoride particle 100 and are isolated inside the magnesium fluoride particle 100.

The pores 130 of the fine particles 110 are formed in the process of manufacturing the magnesium fluoride particles 100. By thermally decomposing the magnesium fluorosilicate crystal, SiF ₄ gas is generated from the magnesium fluorosilicate crystal and discharged out of the magnesium fluorosilicate crystal to generate a magnesium fluoride crystal. By exhausting the gas, pores are formed in the magnesium fluoride crystal. Further, when the gas is discharged, the volume of the magnesium fluorosilicate crystal changes, and the generated magnesium fluoride crystal is refined to become fine particles, and at the same time, the fine particles maintain aggregation or the fine particles newly aggregate.

  The magnesium fluoride fine particles are fused together by heat treatment to form magnesium fluoride particles. Magnesium fluoride particles formed by fusing fine particles can include agglomerated particles of fine particles. By pulverizing such magnesium fluoride particles, the magnesium fluoride particles 100 can be obtained.

Of the pores 130, the fine particle open pores 130 a and the fine particle closed pores 130 b are formed when the SiF ₄ gas is discharged from the magnesium fluorosilicate crystal. The fine pores 130a are also traces of gas discharge. The gas used during the heat treatment (for example, an inert gas such as nitrogen gas or air) can remain and be supported in the fine particle open pores 130a and the fine particle closed pores 130b. The liquid and solvent used in the process of producing the magnesium fluoride particles 100 can also be carried in the fine particle open pores 130a and the fine particle closed pores 130b.

Of the pores 130, the intra-fine particle closed pores 130b are formed not only when the SiF ₄ gas is discharged but also when the opening portion of the intra-fine particle open pores 130a is closed during the crystal growth of the magnesium fluoride fine particles by heat treatment. For example, the closed fine pores 130b are formed by deforming the open fine pores 130a and closing the openings on the surface of the fine particles 110. The closed fine pores 130b can carry a gas (for example, atmospheric gas such as nitrogen gas or air) confined inside the fine pores in the process of closing the opening portion of the open fine pores 130a. The liquid and solvent used in the production process of the magnesium fluoride particles 100 can also be carried in the fine pores 130b.

  The intergranular void-like open pores 130c are formed in the course of aggregation and fusion of magnesium fluoride fine particles by heat treatment. The grain boundary void-shaped open pores 130c can carry a liquid, a solvent, or a gas (for example, an atmospheric gas such as nitrogen gas or air) used in the process of generating the magnesium fluoride particles 100.

  The grain boundary void closed pores 130d are formed by closing the opening portions of the grain boundary void open pores 130c in the course of aggregation and fusion of the magnesium fluoride fine particles. A gas (for example, an atmospheric gas such as nitrogen gas or air) can be carried in the intergranular void-like closed pores 130d in the course of aggregation and fusion of the magnesium fluoride fine particles. The liquid and solvent used in the production process of the magnesium fluoride particles 100 can also be carried in the grain boundary void-shaped closed pores 130d. A supported body having a refractive index lower than that of the fine particles 110 can be supported in the intergranular void-like closed pores 130d.

  FIG. 3 shows a transmission electron microscope (TEM) image of magnesium fluoride particles 100 according to an embodiment of the present invention. The magnesium fluoride particles 100 were photographed with a magnification of 500,000 times by TEM (manufactured by Hitachi, Ltd., HF-2000) to obtain a photographic projection.

[Method for producing magnesium fluoride particles]
FIG. 4 is a flowchart illustrating a method for manufacturing magnesium fluoride particles 100 according to an embodiment of the present invention. Magnesium fluoride particles 100 can be manufactured by executing Steps S302 to S316. By executing Steps S302 to S306, magnesium fluorosilicate particles can be generated. By executing step S308, a slurry of magnesium fluorosilicate fine particles can be generated. By executing step S310, magnesium fluorosilicate crystals can be generated. By executing step S312, a magnesium fluoride crystal can be generated. By executing step S314, a slurry of magnesium fluoride fine particles can be generated. Furthermore, the magnesium fluoride particle 100 can be produced | generated by performing step S316. In this embodiment, Steps S302 to S310 function as a preparation process for preparing a magnesium fluorosilicate crystal. Hereinafter, the manufacturing method of the magnesium fluoride particles 100 will be described with reference to FIG.

  Step S302: A magnesium salt and a solution containing silicofluoride ions are mixed to produce a magnesium silicofluoride particle aggregate slurry. The mixing temperature is 50 ° C. or higher and 90 ° C. or lower.

  The magnesium salt is, for example, at least one of magnesium chloride, magnesium carbonate, magnesium hydroxide, magnesium sulfate, magnesium acetate, magnesium sulfamate, magnesium formate, magnesium citrate, magnesium benzoate, and magnesium oxalate. A seed | species can be used independently or 2 or more types can be mixed and used. The silicofluoride ion is, for example, at least one of silicofluoride ions dissociated and produced from silicofluoride (sodium silicofluoride, potassium silicofluoride, cesium silicofluoride, hydrogen silicofluoride, ammonium silicofluoride, quaternary ammonium silicofluoride, etc.). It is a seed, and one kind can be used alone, or two or more kinds can be mixed and used.

  Although not particularly limited, in order to efficiently produce a magnesium silicofluoride particle aggregate slurry, the molar ratio between silicofluoride ions and magnesium ions dissociated and produced from magnesium salts is preferably near the stoichiometric ratio. Specifically, the value of silicofluoride ion / magnesium ion is preferably 1.0 or more and 2.0 or less. More preferably, the value of silicofluoride ion / magnesium ion is 1.0 or more and 1.5 or less.

  As a method of mixing the magnesium salt and the solution containing silicofluoride ions, there is a method of mixing a solution containing silicofluoride ions into an aqueous solution generated by dissolving magnesium salt in water in advance. Although not particularly limited, a method of mixing magnesium salt with a solution containing silicofluoride ions is preferable. This is because when compared with a method in which a solution containing silicofluoride ions is mixed with a magnesium salt, the size of magnesium silicofluoride particles contained in the obtained aggregate slurry is easily made uniform. In addition, it is easier to make the size of the magnesium fluorosilicate particles contained in the aggregate slurry uniform by slowly mixing at a constant speed rather than mixing all at once.

  The mixing temperature may be 0 ° C. or higher and 100 ° C. or lower, but is preferably 50 ° C. or higher and 90 ° C. or lower. When the mixing temperature is set to 50 ° C. or higher, the generation of crystal water contained in a large amount of the generated magnesium silicofluoride can be suppressed. As a result, whitening of the coating film formed by coating the organosol of the magnesium fluoride particles 100 into a paint can be suppressed. When the mixing temperature is 90 ° C. or lower, it is possible to prevent the particle size of the magnesium fluorosilicate particles contained in the aggregate slurry from becoming too large.

  The mixing time is preferably 0.1 hour or more and 1 hour or less. When the mixing time is 0.1 hour or more, the magnesium salt and the solution containing the silicofluoride ions are easily mixed uniformly. If the mixing time is 1 hour or less, it is possible to prevent the particle size of the magnesium fluorosilicate particles contained in the aggregate slurry from becoming too large. Further, the productivity of the magnesium fluoride particles 100 can be improved.

  Step S304: The magnesium silicofluoride particle aggregate slurry is washed to produce a magnesium silicofluoride particle paste.

  Washing of the magnesium silicofluoride particle aggregate slurry means removing unreacted substances and by-products contained in the magnesium silicofluoride particle aggregate slurry. Although unreacted substances and by-products can be removed by suction filtration, pressure filtration, centrifugation, etc., the present invention is not limited to these as long as the unreacted substances and by-products can be removed. Furthermore, the conductivity of the waste liquid after washing is preferably 1.0 mS / cm or less. If it is 1.0 mS / cm or less, unreacted substances and by-products do not cause dispersion inhibition. Further, by removing moisture by suction filtration, pressure filtration, centrifugation, or the like, a magnesium silicofluoride particle paste can be generated from the magnesium silicofluoride particle aggregate slurry, and it becomes easy to perform drying in the next step.

  Step S306: The magnesium silicofluoride particle paste is dried to produce magnesium silicofluoride particles. The drying temperature is 50 ° C. or higher and 110 ° C. or lower.

The moisture of the magnesium silicofluoride particle paste is further removed to obtain powdered magnesium silicofluoride particles. Examples of a method for obtaining a powder by removing moisture from the paste of magnesium silicofluoride particles include drying under reduced pressure and heat drying using an oven. In order to suppress dry aggregation, it is preferable to dry in an inert gas (for example, N ₂ gas) atmosphere of 50 ° C. or higher and 110 ° C. or lower. Furthermore, in order to suppress dry aggregation, a drying device (such as a spray dryer) may be used. Further, in order to lower the drying temperature, the water contained in the paste of magnesium silicofluoride particles can be replaced with a hydrophilic and low-boiling organic solvent (methanol, ethanol, acetone, etc.).

  Step S308: Magnesium silicofluoride particles are mixed with the solution, and the magnesium silicofluoride particles are pulverized to produce a slurry of magnesium silicofluoride particles. The average particle diameter of the magnesium fluorosilicate fine particles is 1 nm or more and 100 nm or less. A bead mill was used as a disperser.

  The solution particularly refers to an organic solution, and the solution is, for example, a dispersion medium having an acidic functional group or a liquid organic substance. The solution can be a dispersion medium containing an organic solution. As the dispersion medium, a mixed medium of water and a water-soluble organic solution is usually used. As an example of the water-soluble organic solution, isopropanol can be practically used. Moreover, in order to promote the dispersibility of the magnesium fluorosilicate particles, a dispersant (such as a surfactant) can be appropriately added to the dispersion medium.

  As the dispersant, a nonionic or anionic hydrocarbon dispersant or a nonionic or anionic fluorine dispersant can be used. From the viewpoint of long-term stability of the dispersed state, the dispersant is, for example, at least one of polyoxyethylene tridecyl ether phosphate, polyoxyethylene isodecyl ether, sorbitan monooleate, and polyvinyl pyrrolidone. A seed | species can be used independently or 2 or more types can be mixed and used.

  The solid content concentration in the dispersion medium is usually in the range of 1 to 15% by mass, preferably in the range of 2 to 10% by mass, and more preferably in the range of 2 to 8% by mass. It is a range. When the solid content concentration in the dispersion medium is 1% by mass or more, the efficiency in the process is practical. When the solid content concentration in the dispersion medium is 15% by mass or less, a good dispersion state can be easily obtained.

  Dispersers for pulverizing magnesium silicofluoride particles include, for example, paint conditioners (manufactured by Red Devil), ball mills, sand mills, bead mills (“Dino Mill” manufactured by Shinmaru Enterprises, “MSC100” manufactured by Nippon Coke Industries, Ltd.), Lighter, pearl mill (such as “DCP mill” manufactured by Eirich), coball mill, homomixer, homogenizer (such as “Clairemix” manufactured by M Technique), wet jet mill (“Genus PY” manufactured by Genus, “Nanomizer manufactured by Nanomizer” Or the like. In addition, after performing dry processing such as attritor or two rolls on the mixed liquid of paste-like magnesium silicofluoride particles and dispersant having acidic functional group, an organic solvent is added and dispersed with a disperser. obtain. In addition, when using a medium for a disperser, a zirconia bead etc. are preferable as a medium.

  Step S310: The magnesium silicofluoride fine particle slurry is evaporated to dryness to produce magnesium fluorosilicate crystals. The evaporation to dryness temperature is 50 ° C. or higher and 110 ° C. or lower. It is preferable to perform evaporation to dryness in the same manner as the drying performed in step S306 to obtain a magnesium fluorosilicate crystal powder.

Step S312: The magnesium fluorosilicate crystal is heat treated to produce a magnesium fluoride crystal. The heat treatment is preferably performed in an inert gas (eg, N ₂ gas) atmosphere of 300 ° C. or higher and 900 ° C. or lower. More preferably, the heat treatment is performed in an inert gas (for example, N ₂ gas) atmosphere of 400 ° C. or higher and 900 ° C. or lower. When the heat treatment temperature is 300 ° C. or higher, there is no concern about the remaining undecomposed magnesium fluorosilicate, and when the heat treatment temperature is 900 ° C. or lower, the growth of decomposed magnesium fluoride crystals is suppressed, and a significant increase in particle size is prevented. Can do. In addition, since heat treatment is performed in an inert gas atmosphere, generation of oxides or the like is not a concern.

  The heat treatment time is preferably 1 hour or more and 8 hours or less, and more preferably 3 hours or more and 8 hours or less. When the heat treatment time is 1 hour or longer, there is no concern about the remaining undecomposed magnesium silicofluoride, and when the heat treatment time is 8 hours or less, the growth of decomposed magnesium fluoride crystals is suppressed, and a significant increase in particle size is prevented. be able to. In addition, when a low refractive index layer is formed using a magnesium fluoride particle dispersion containing undecomposed magnesium silicofluoride, there is a concern that the resin contained in the low refractive index layer may be deteriorated by an acid.

  Step S314: The magnesium fluoride crystal is mixed with the solution, and the magnesium fluoride crystal is pulverized to generate a magnesium fluoride fine particle slurry. The average particle diameter of the magnesium fluoride fine particles is 1 nm or more and 100 nm or less. A bead mill was used as a disperser.

  The solution particularly refers to an organic solution, and the solution is, for example, a dispersion medium having an acidic functional group or a liquid organic substance. The solution can be a dispersion medium containing an organic solution. As the organic solution, it is preferable to use a solution similar to the solution used when executing Step S308.

  The solid content concentration in the dispersion medium is usually in the range of 1 to 15% by mass, preferably in the range of 2 to 10% by mass, and more preferably in the range of 2 to 8% by mass. It is a range. When the solid content concentration in the dispersion medium is 1% by mass or more, the efficiency in the process is practical. When the solid content concentration in the dispersion medium is 15% by mass or less, a good dispersion state can be easily obtained.

  Step S316: After evaporating and drying the magnesium fluoride fine particle slurry, heat treatment is performed to generate the magnesium fluoride particles 100. The evaporation to dryness temperature is 50 ° C. or higher and 110 ° C. or lower. It is preferable to obtain the magnesium fluoride particles 100 by performing evaporation to dryness by a method similar to the evaporation to dryness performed in step S310 and further performing heat treatment by the same method as the heat treatment performed in step S312.

However, the heat treatment is preferably performed at 200 ° C. or higher and 400 ° C. or lower and in an inert gas (eg, N ₂ gas) atmosphere. When the heat treatment temperature is 200 ° C. or higher, there is no concern about the remaining of the solvent. When the heat treatment temperature is 400 ° C. or lower, crystal growth of the magnesium fluoride particles 100 can be suppressed and a significant increase in particle diameter can be prevented. In addition, since heat treatment is performed in an N ₂ gas atmosphere, generation of oxides and the like is not a concern. When the heat treatment time is 1 hour or longer, there is no concern about the remaining of the solvent, and when the heat treatment time is 3 hours or less, crystal growth of the magnesium fluoride particles 100 can be suppressed and a significant increase in particle diameter can be prevented.

  The steps S302 to S316 have been described above with reference to FIG. Magnesium silicofluoride is a scaly crystal, and an aggregate of magnesium silicofluoride particles is obtained by executing step S302. The particle diameter of the aggregate is several hundred nm to several tens of μm, but the average particle diameter of the particles forming the aggregate (referred to as primary particles) is 50 nm or less. Aggregates of magnesium silicofluoride particles can be easily dispersed into primary particles (average particle diameter of 1 nm to 50 nm) by a bead mill. Aggregation of particles occurs again by the evaporation to dryness executed in step S310, and a magnesium fluorosilicate crystal can be obtained.

Furthermore, by the heat treatment performed in step S312, the magnesium fluorosilicate crystal can be thermally decomposed to obtain a magnesium fluoride crystal. In the thermal decomposition reaction, SiF ₄ gas is generated from the magnesium silicofluoride crystal and discharged out of the magnesium silicofluoride crystal to produce a magnesium fluoride crystal. By exhausting the gas, pores are formed in the magnesium fluoride crystal. Further, when the gas is discharged, the volume of the magnesium fluorosilicate crystal changes, and the generated magnesium fluoride crystal is refined to become fine particles, and at the same time, the fine particles maintain aggregation or the fine particles newly aggregate.

  Magnesium fluoride fine particles grow by heat treatment to form magnesium fluoride particles. Fine particles agglomerate or fuse in the course of particle growth. Magnesium fluoride particles formed by agglomeration and fusion of fine particles can include fine particle aggregates and fine particles in which the fine particles are fused. By pulverizing the magnesium fluoride particles, the magnesium fluoride particles 100 having an average particle diameter of 1 nm or more and 100 nm or less can be obtained.

[Magnesium fluoride particle dispersion]
FIG. 5 is a schematic view showing a magnesium fluoride particle dispersion 200 according to an embodiment of the present invention. In FIG. 5, a magnesium fluoride particle dispersion 200 includes magnesium fluoride particles 100 and a dispersion medium 210 and is put in a container A. Magnesium fluoride particles 100 are dispersed in a dispersion medium 210. The magnesium fluoride particle dispersion 200 is a sol-like dispersion using the magnesium fluoride particles 100 as a dispersoid, and may be referred to as a magnesium fluoride sol.

  The dispersion medium 210 is water or an organic dispersion. Organic dispersions include, for example, alcohols (methanol, ethanol, isopropanol, butanol, etc.), ketones (acetone, MEK, MIBK, etc.), esters (ethyl acetate, butyl acetate, etc.), aromatics (toluene, xylene, etc.) ), Ethers (methyl cellosolve, ethyl cellosolve, etc.), and one kind can be used alone, or two or more kinds can be used in combination. Further, the dispersion medium 210 can be a mixed dispersion of an organic dispersion and water. In addition, when applying the magnesium fluoride particle dispersion 200 to the composition for forming the low refractive index layer, use an organic dispersion having a volatility that does not hinder the formation of the low refractive index layer. Is desirable.

  The solid content concentration in the magnesium fluoride particle dispersion 200 is usually in the range of 1 to 15% by mass, preferably in the range of 1 to 10% by mass, and more preferably in the range of 2 to 8% by mass. It is the range of the mass% or less. If the solid content concentration in the magnesium fluoride particle dispersion 200 is 1% by mass or more, the concentration is not too dilute and no concentration treatment is required. In addition, when the solid content concentration in the magnesium fluoride particle dispersion 200 is 15% by mass or less, the magnesium fluoride particles 100 are not easily aggregated, and a good dispersion state can be easily obtained.

[Method for producing magnesium fluoride particle dispersion]
FIG. 6 is a flowchart showing a method for manufacturing a magnesium fluoride particle dispersion 200 according to an embodiment of the present invention. The magnesium fluoride particle dispersion 200 can be manufactured by executing Steps S302 to S316 and Step S502. Steps S302 to S316 are the same as the steps described with reference to FIG.

  Magnesium fluoride particles 100 are obtained by executing steps S302 to S316.

  Step S502: The magnesium fluoride particles 100 are dispersed in the dispersion medium 210 to obtain the magnesium fluoride particle dispersion 200.

  In addition, execution of step S316 and step S502 of step S302 to step S316 can be omitted by using the solution used when executing step S314 as the dispersion medium 210.

  Further, in order to improve the dispersibility of the magnesium fluoride particles 100, a dispersant (such as a surfactant) can be appropriately added to the dispersion medium 210. As the dispersant, a nonionic or anionic hydrocarbon dispersant or a nonionic or anionic fluorine dispersant can be used as in step S308. From the viewpoint of long-term stability of the dispersed state, the dispersant is, for example, at least one of polyoxyethylene tridecyl ether phosphate, polyoxyethylene isodecyl ether, sorbitan monooleate, and polyvinyl pyrrolidone. A seed | species can be used independently or 2 or more types can be mixed and used.

[Composition 300 for forming a low refractive index layer]
FIG. 7 is a schematic diagram showing a composition 300 for forming a low refractive index layer according to an embodiment of the present invention. In FIG. 7, the composition 300 for forming a low refractive index layer includes magnesium fluoride fine particles 100 and a binder 310 and is put in a container A.

  The binder 310 is a layer forming material in which the magnesium fluoride particles 100 are dispersed, and may be a conventionally known binder. The binder 310 is at least one of, for example, a coating resin, a polymerizable monomer, a hydrolyzable organometallic compound, and a silicic acid solution (sodium silicate, etc.). It can be used by mixing more than one species.

  There is no restriction | limiting in particular as resin for coating materials, It can be general resin (a well-known thermosetting resin, a well-known thermoplastic resin, etc.). The resin for paint is, for example, acrylic resin, polyester resin, polycarbonate resin, polyamide resin, urethane resin, vinyl chloride resin, fluororesin, silicon resin, epoxy resin, melamine resin, phenol resin, butyral resin, vinyl acetate resin It is at least one, and one can be used alone, or two or more can be used as a copolymer or a modified product. The coating resin can be, for example, a resin containing fluorine atoms in order to lower the refractive index of the coating film.

  The polymerizable monomer is not particularly limited as long as it is a polymerizable monomer (radical polymerization, anionic polymerization, cationic polymerization, etc.), and may be a general monomer. Polymerizable monomers include, for example, nonionic monomers (styrene, methyl methacrylate, 2-hydroxyethyl acrylate, etc.), anionic monomers (methacrylic acid, maleic acid, itaconic acid, 2-acrylamido-2-methylpropanesulfonic acid, o -And p-styrene sulfonate, and salts thereof), cationic monomers (N- (3-acrylamidopropyl) ammonium methacrylate, N- (2-methacryloyloxyethyl) -N, 1,2-dimethyl-5-vinyl Pyridinium methosulphate, and salts thereof) and crosslinking monomers (divinylbenzene, ethylene diacrylate, N, N-methylenebisacrylamide, etc.). Mixing more than seeds Or can. The polymerizable monomer can be, for example, a monomer containing a fluorine atom in order to lower the refractive index of the coating film.

Hydrolyzable organometallic compounds include alkoxides (general formula R ¹ _n M _m (OR ² ) _mn [wherein R ¹ , R ² : hydrocarbon groups such as alkyl groups, aryl groups, vinyl groups, acrylic groups, M: metal atom, m = coordination number of element, n = 0, 1, 2, or 3], or at least one of derivatives thereof, One kind can be used alone, or two or more kinds can be mixed and used. In addition, hydrolyzable organometallic compounds include organic silicon compounds (tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, ethyltriisopropoxysilane, vinyltriethoxysilane). Etc.).

  In order to adjust the viscosity and the solid content, an organic solvent can be added to the composition 300 for forming a low refractive index layer. The organic solvent that can be added can be selected in consideration of the compatibility with the organic solvent that is the dispersion medium of the organosol of the magnesium fluoride particles 100 and the compatibility with the binder 310. The organic solvent that can be added is, for example, at least one of an alcohol solvent, a ketone solvent, an ether solvent, an ester solvent, a halogen solvent, and a hydrocarbon solvent, and can be used alone. Two or more kinds can be mixed and used.

[Method for producing composition for forming low refractive index layer]
FIG. 8 is a flowchart showing a method for manufacturing the composition 300 for forming a low refractive index layer according to an embodiment of the present invention. The composition 300 for forming a low refractive index layer can be manufactured by executing Steps S702 to S712.

  Step S702: With respect to 5% magnesium fluoride particle dispersion 200 containing magnesium fluoride particles 100 (379 parts by mass) and dispersion medium 210 (isopropyl alcohol 7204 parts by mass), methyltrimethoxysilane (200 parts by mass), Trifluoropropyltrimethoxysilane (150 parts by mass) and polypropylene glycol monoethyl ether (700 parts by mass) were stirred and mixed to produce a mixed solution.

  Step S704: Phosphoric acid (1 part by mass) and water (150 parts by mass) were blended with the mixed solution to produce a blended solution.

  Step S706: The blended solution was hydrolyzed for 60 minutes with stirring at 30 ° C. ± 5 ° C. to produce a hydrolyzed solution.

  Step S708: The temperature was further raised to 80 ° C. ± 3 ° C., and the hydrolyzate was polymerized while stirring for 60 minutes to prepare a polymer containing magnesium fluoride particles 100.

  Step S710: A polymer (654 parts by mass) containing magnesium fluoride particles 100 and isopropyl alcohol (390 parts by mass) were stirred and mixed to produce a stirred mixture.

  Step S712: Acetoxyaluminum (15 parts by mass) as a curing catalyst was added to the stirred mixed solution and mixed again with stirring to prepare a low refractive index layer forming composition 300 (low refractive index paint). The refractive index of the coating film of the composition 300 for forming a low refractive index layer was 1.35.

[Substrate with low refractive index layer]
FIG. 9 is a schematic view showing a substrate 400 with a low refractive index layer according to an embodiment of the present invention. The substrate 400 with a low refractive index layer includes a low refractive index layer 410, a hard coat layer 420, and a resin substrate 430. The low refractive index layer 410 includes the low refractive index layer forming composition 300. A hard coat layer 420 is formed on the resin substrate 430, and a low refractive index layer 410 is formed on the hard coat layer 420.

  The low refractive index layer 410 is formed by applying the low refractive index layer forming composition 300 (low refractive index paint) on the hard coat layer 420. The method for applying the composition 300 for forming a low refractive index layer is not particularly limited, and for example, at least one of a dipping method, a spray method, a spinner method, and a roll coating method can be used. The low refractive index layer 410 can be formed by applying the low refractive index layer forming composition 300 and then drying the low refractive index layer forming composition 300. In addition, according to the kind of binder 310, hardening of the hard-coat layer 420 can be accelerated | stimulated by performing heat processing or an ultraviolet irradiation process.

  The amount of the magnesium fluoride particles 100 contained in the low refractive index layer 410 may be 20% by mass or more and 90% by mass or less with respect to 100% by mass of the total amount of the low refractive index layer 410. When the content of the magnesium fluoride particles 100 as a low refractive index component is 90% by mass or less, a decrease in physical and chemical strength of the low refractive index layer 410 is suppressed, and adhesion to the hard coat layer 420 is suppressed. To satisfy the practicality. Further, when the content of the magnesium fluoride particles 100 is 20% by mass or more, the effect of lowering the refractive index of the low refractive index layer 410 can be maintained, which is practical.

  The thickness of the low refractive index layer 410 is 50 nm or more and 300 nm or less, preferably 80 nm or more and 200 nm or less. When the thickness of the low refractive index layer 410 is 50 nm or more, it is easy to suppress a decrease in strength of the low refractive index layer 410 or a decrease in antireflection performance. Further, when the thickness of the low refractive index layer 410 is 300 nm or less, generation of cracks in the low refractive index layer 410 is suppressed, strength reduction of the low refractive index layer 410 is suppressed, or the low refractive index layer 410 is suppressed. It is easy to suppress a decrease in antireflection performance due to being too thick.

  The refractive index of the low refractive index layer 410 varies depending on the mixing ratio of the magnesium fluoride particles 100 that are the low refractive index component and the binder 310 that is the low refractive index layer forming component, but is 1.28 or more and 1.50 or less. Is preferable, the range of 1.30 to 1.42 is more preferable, and the range of 1.30 to 1.40 is particularly preferable.

  When the refractive index of the low refractive index layer 410 is 1.50 or less, it is easy to suppress a decrease in antireflection performance. In addition, it is relatively easy to obtain the low refractive index layer 410 having a refractive index of 1.28 or more.

  The hard coat layer 420 includes high refractive index particles and a coat layer forming component, and functions as a high refractive index layer. The high refractive index particles are particles having a refractive index of 1.6 or more and made of, for example, a metal, a metal oxide, or a metal fluoride. The high refractive index particles are, for example, at least one of zinc, titanium, aluminum, cerium, yttrium, niobium, zirconium, antimony, indium and tin, and can be used alone or in combination of two or more. Can be used. The coating layer forming component is, for example, at least one of an active energy ray-curable acrylic resin and a thermosetting acrylic resin, and can be used alone or in combination of two or more. Can be used.

  The thickness (Th) of the hard coat layer 420 is 300 nm or more. The ratio (Dp / Th) of the average particle diameter (Dp) of the high refractive index particles to the thickness (Th) of the hard coat layer 420 is preferably in the range of 0.2 to 1.0. Further, the difference between the refractive index of the high refractive index particles and the refractive index of the coating layer forming component is usually 0.2 or less, preferably 0.1 or less.

  For example, the resin substrate 430 may be one of a plastic sheet, a plastic film, and a plastic panel. Moreover, the material which comprises the resin substrate 430 is at least 1 sort (s) of a polycarbonate, an acrylic resin, PET, and a triacetyl cellulose (TAC), for example, can be used individually or can mix 2 or more types. Can be used.

[Production Method of Substrate with Low Refractive Index Layer]
The substrate 400 with a low refractive index layer is manufactured by laminating a hard coat layer 420 on a resin substrate 430 and laminating a low refractive index layer 410 on the hard coat layer 420. As a method of laminating the low refractive index layer 410 on the hard coat layer 420, there is a method of laminating a film produced using the low refractive index layer forming composition 300 on the hard coat layer 420. The lamination method is, for example, a method of directly laminating on the hard coat layer 420 by coating the hard coat layer 420 with the composition 300 for forming a low refractive index layer, or a low refractive index formed on a substrate different from the resin substrate 430. It is at least one of methods for laminating the layer 410 on the hard coat layer 420 by transfer.

  The coating method is at least one of general coating methods, for example, reverse coating method, gravure coating method, rod coating method, bar coating method, die coating method, and spray coating method, and one type is used alone. Or 2 or more types can be mixed and used. In forming the low refractive index layer 410, a reverse coating method, particularly a reverse coating method using a small-diameter gravure roll, is preferable from the viewpoint of coating accuracy.

  In addition, when the low refractive index layer 410 is laminated on the hard coat layer 420, the paint is adjusted by dispersing the low refractive index layer forming composition 300 with a solvent, and the paint is applied to the hard coat layer 420. It is preferable to dry and cure the paint. The solvent is blended to improve the coating or printing workability, and any conventionally known solvent can be used as long as it is a solvent that dissolves the binder 310.

  Solvents include, for example, methanol, ethanol, isopropyl alcohol, n-butanol, tert-butanol, ethylene glycol monomethyl ether, 1-methoxy-2-propanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, cyclohexanone, butyl acetate, isopropyl It is at least one of acetone, methyl ethyl ketone, methyl isobutyl ketone, diacetylacetone, and acetylacetone, and can be used alone or in combination of two or more. The hard coat layer 420 can be applied by the same method as the application of the low refractive index layer 410.

  The amount of the solvent used is not particularly limited as long as it is in a range suitable for the formation of the low refractive index layer 410, but usually, with respect to a total of 100 parts by mass of the magnesium fluoride particles 100 and the binder 310, A solvent is the range of 10 mass parts or more and 10000 mass parts or less. In addition, coloring agents, such as dye and a pigment, can be added to a solvent.

  As mentioned above, with reference to FIGS. 1-9, the manufacturing method of the magnesium fluoride particle 100 which concerns on embodiment of this invention, the magnesium fluoride particle 100, the magnesium fluoride particle dispersion 200, and the magnesium fluoride particle dispersion 200 The production method, the composition 300 for forming a low refractive index layer, the production method for the composition 300 for forming a low refractive index layer, the substrate 400 with a low refractive index layer and the method for producing the substrate 400 with a low refractive index layer have been described.

[Example]
Examples 1 to 4 according to the embodiment of the present invention will be described below. Furthermore, for comparison with Examples, Comparative Example 1 and Comparative Example 2 to which the conventional technique is applied will be described. In addition, the measuring method of the average particle diameter of the magnesium fluoride particle formed by performing Example 1-4, Comparative Example 1, and Comparative Example 2, the refractive index of particle | grains, and the specific surface area of particle | grains is as follows. It is.

[Average particle size measurement]
The average particle diameter of the magnesium fluoride particles was measured by a dynamic light scattering method. Specifically, magnesium fluoride particles and isopropyl alcohol are mixed to prepare a colloid having a magnesium fluoride concentration of 5% by mass, and a particle size distribution measuring device (Nikkiso Co., Ltd., Microtrac, Nanotrac UPA, UPA-UZ152) is used. The average particle size of the magnesium fluoride particles was measured. In addition, an average particle diameter is a particle diameter defined by 50 volume percent of the whole sample particle | grain consisting of particles below an average particle diameter (d50).
Measurement principle: Dynamic light scattering method Frequency analysis (FFT-heterodyne method)
Light source: 3mW Semiconductor laser 780nm (2)
Setting range: 10 ℃ ~ 80 ℃
Measurement particle size distribution range: 0.8 nm to 6.5406 μm
Measurement object: colloidal particles Unless otherwise specified, the average particle diameter in the examples and comparative examples according to the embodiments of the present invention means the volume-converted average particle diameter measured by the dynamic light scattering method described above. .

[Refractive index measurement of particles]
A method for measuring the refractive index of the magnesium fluoride particles will be described below. Specifically, step S202 and step S204 are executed.

  Step S202: A standard refractive index liquid (Cargill standard refractive liquid, series AA and AAA) having a known refractive index is dropped on a glass substrate, and magnesium fluoride particles are mixed with the standard refractive index liquid. To prepare.

  Step S204: Step S202 is performed on various standard refractive index liquids (n = 1.300 to 1.458, wavelength = 589.3 nm) as a target, thereby adjusting a plurality of types of liquid mixture and mixing to become transparent The refractive index of the standard refractive index liquid contained in the liquid was taken as the refractive index of the magnesium fluoride particles.

[Specific surface area measurement of particles]
The specific surface area of the magnesium fluoride particles was measured by a nitrogen adsorption method (BET method). Specifically, the specific surface area of the magnesium fluoride particles was measured by the BET method using a specific surface area measurement device (manufactured by Shimadzu Corporation Micrometrics; Gemini V). Magnesium fluoride particles (about 1 g) were dried under reduced pressure and further degassed to obtain a sample for measurement. The drying temperature is 150 ° C. and the drying time is about 20 hours.

  Examples 1 to 4 according to the embodiment of the present invention will be described below. Furthermore, for comparison with Examples, Comparative Example 1 and Comparative Example 2 to which the conventional technique is applied will be described.

[Example 1]
[Formation of magnesium fluorosilicate particles]
By executing steps S302 to S306 described with reference to FIG. 4, magnesium fluorosilicate particles are generated.

H ₂ SiF ₆ aqueous solution (40%: 897.4g) weighed to put in a reaction vessel (made PFA), and after the liquid temperature at 80 ° C. by a water bath, MgCO ₃ with stirring maintaining the liquid temperature to 80 ° C. (200 g: manufactured by Kamishima Co., Ltd.) was continuously added in small portions over about 30 minutes to obtain a reaction solution. Thereafter, the reaction solution was aged for 1 hour while keeping the temperature of the reaction solution at 80 ° C.

  Remove the reaction vessel from the water bath and leave it for about 2 hours. When the reaction solution reaches room temperature (20-23 ° C.), add isopropanol (645.2 g: reagent grade product manufactured by Wako Pure Chemical Industries, Ltd.). The mixture was sufficiently stirred to obtain a stirred reaction solution. The stirred reaction liquid was subjected to suction filtration with a membrane filter (pore size 5 μm: manufactured by Millipore) for about 2 hours, and a magnesium silicofluoride particle paste (678.2 g) was obtained as a filtration residue.

The magnesium silicofluoride particle paste was placed in a reaction vessel (manufactured by PFA) and dried using a drier while flowing high purity N ₂ gas (flow rate 5 L / min) into the reaction vessel (manufactured by PFA) (drying temperature 60 ° C, drying time 50 hr). After drying, 484.7 g of white powder was obtained. When the white powder was analyzed by XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgSiF ₆ .6H ₂ O. Further, as a result of TG measurement of the powder using a thermobalance (EXSTAR6000 TG / DTA6300 manufactured by Seiko), it was confirmed that the powder was a 6H ₂ O salt. The yield of MgSiF ₆ · 6H ₂ O was 74%.

[Slurry production of magnesium fluorosilicate fine particles]
By executing step S308 described with reference to FIG. 4, a slurry of magnesium fluorosilicate fine particles is generated.

The white powder (MgSiF ₆ .6H ₂ O: 480 g) obtained by executing Step S306 is added to isopropanol (5920 g: reagent special grade manufactured by Wako Pure Chemical Industries, Ltd.) and stirred sufficiently to obtain a solution (7. 5%: 6400 g). The powder was pulverized by a bead mill (manufactured by Shinmaru Enter Co., Ltd.), and the average particle size of the powder was adjusted to 20 nm or less. The powder was pulverized several times to produce a MgSiF ₆ .6H ₂ O fine particle dispersion (magnesium silicofluoride fine particle slurry). The weight of the MgSiF ₆ · 6H ₂ O fine particle dispersion was about 6100 g, and the concentration of the MgSiF ₆ · 6H ₂ O fine particle dispersion was 7.5%.

[Formation of magnesium silicofluoride crystals]
By executing step S310 described with reference to FIG. 4, a magnesium fluorosilicate crystal is generated.

6000 g of MgSiF ₆ .6H ₂ O fine particle dispersion (7.5%) obtained by executing Step S308 is filled in a reaction vessel (made by PFA), and an N ₂ gas inlet and an exhaust outlet are attached. Covered the lid. The MgSiF ₆ .6H ₂ O fine particle dispersion was dried using a drier while flowing N ₂ gas (flow rate: ₂ L / min) into the reaction vessel (manufactured by PFA) (drying temperature 80 ° C., drying time 72 hours). After drying, about 445 g of white powder (magnesium fluorosilicate crystal: MgSiF ₆ .6H ₂ O) was obtained.

[Formation of magnesium fluoride crystals]
By performing step S312 described with reference to FIG. 4, a magnesium fluoride crystal is generated.

Of the white powder (magnesium fluorosilicate crystal) obtained by executing Step S310, 430 g was filled in an alumina crucible, and the white powder was heat-treated in an N ₂ gas atmosphere using an electric furnace. The heat treatment temperature is 600 ° C., and the heat treatment time is 3 hours. After the heat treatment, the temperature was lowered to room temperature (20 to 23 ° C.) in an N ₂ gas atmosphere, and 79 g of white powder could be taken out from the alumina crucible. When the powder was analyzed by XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgF ₂ (magnesium fluoride crystal). Accordingly, the yield of MgF ₂ (magnesium fluoride crystal) that could be generated from MgSiF ₆ .6H ₂ O was 81%.

[Slurry production of magnesium fluoride fine particles]
By executing step S314 described with reference to FIG. 4, a slurry of magnesium fluoride fine particles is generated.

The white powder (MgF ₂ : 37.5 g) obtained by executing Step S312 is added to isopropanol (462.5 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and sufficiently stirred, and the MgF ₂ dispersion solution (7. 5%: 500 g) was obtained. The MgF ₂ dispersion was dispersed with a bead mill (manufactured by Shinmaru Enter Co., Ltd.) to obtain a dispersion. While performing dispersion treatment using zirconia beads (Nikkato Co., Ltd.), the particle size distribution of MgF ₂ (magnesium fluoride fine particles) in the dispersion was measured using a particle size distribution analyzer (Nikkiso Co., Ltd .: Microtrac UPA-UZ152). It was measured. As a result of dispersion treatment until the average particle diameter (volume conversion, d50) of MgF ₂ became 30 nm or less, 358 g of a fine particle dispersion solution (magnesium fluoride fine particle slurry: 7.5%) of MgF ₂ was obtained.

[Manufacture of magnesium fluoride particles 100]
Magnesium fluoride particles 100 are manufactured by executing step S316 described with reference to FIG.

  The magnesium fluoride fine particle dispersion (magnesium fluoride fine particle slurry: about 358 g) obtained by executing Step S314 is evaporated to dryness at 50 ° C. or higher and 110 ° C. or lower, and then maintained at 200 ° C. or higher and 400 ° C. or lower. Heat treatment was performed to obtain magnesium fluoride particles 100 (about 26 g).

[Production of Magnesium Fluoride Particle Dispersion 200]
By executing step S502 described with reference to FIG. 6, the magnesium fluoride particle dispersion 200 is manufactured.

Magnesium fluoride particles 100 (powder 25 g) obtained by executing Step S316 are added to isopropanol (475 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and sufficiently stirred, and magnesium fluoride particle dispersion 200 (5% : 500 g) was obtained. When the refractive index of the magnesium fluoride particles 100 with respect to light having a wavelength of 550 nm was measured, the refractive index was 1.34. Since the refractive index of single crystal MgF ₂ with respect to light having a wavelength of 550 nm was 1.38, it was confirmed that the magnesium fluoride particles 100 had pores 130.

[Example 2]
[Formation of magnesium fluorosilicate particles]
By executing steps S302 to S306 described with reference to FIG. 4, magnesium fluorosilicate particles are generated.

(NH ₄ ) ₂ SiF ₆ aqueous solution (15%: 3000 g) is weighed and placed in a reaction vessel (manufactured by PFA), and the temperature of the solution is adjusted to 50 ° C. with a water bath. ₃ (200 g: manufactured by Kamishimasha) was continuously added in small portions over about 30 minutes to obtain a reaction solution. Thereafter, the reaction solution was aged for 1 hour while keeping the temperature of the reaction solution at 50 ° C.

  The reaction vessel is taken out of the water bath and allowed to stand for about 2 hours. When the reaction solution reaches room temperature (20-23 ° C.), the reaction solution is passed through a membrane filter (pore size 5 μm: manufactured by Millipore) for about 2 hours. Suction filtration was performed to obtain a magnesium silicofluoride particle paste (718.5 g) as a filtration residue.

The magnesium silicofluoride particle paste was placed in a reaction vessel (manufactured by PFA) and dried using a drier while flowing high purity N ₂ gas (flow rate 5 L / min) into the reaction vessel (manufactured by PFA) (drying temperature 110). ° C, drying time 50 hr). After drying, 462.3 g of white powder was obtained. When the white powder was analyzed by XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgSiF ₆ .6H ₂ O. Further, as a result of TG measurement of the powder using a thermobalance (EXSTAR6000 TG / DTA6300 manufactured by Seiko), it was confirmed that the powder was a 6H ₂ O salt. The yield of MgSiF ₆ .6H ₂ O was 71%.

[Slurry production of magnesium fluorosilicate fine particles]
By executing step S308 described with reference to FIG. 4, a slurry of magnesium fluorosilicate fine particles is generated.

The white powder (MgSiF ₆ .6H ₂ O: 460 g) obtained by executing Step S306 was added to isopropanol (6111 g: reagent special grade manufactured by Wako Pure Chemical Industries, Ltd.) and stirred well to obtain a solution (7% ) The powder was pulverized by a bead mill (manufactured by Shinmaru Enter Co., Ltd.), and the average particle size of the powder was adjusted to 20 nm or less. The powder was pulverized several times to produce a MgSiF ₆ .6H ₂ O fine particle dispersion (magnesium silicofluoride fine particle slurry). The weight of the MgSiF ₆ · 6H ₂ O fine particle dispersion was about 5880 g, and the concentration of the MgSiF ₆ · 6H ₂ O fine particle dispersion was 7%.

[Formation of magnesium silicofluoride crystals]
By executing step S310 described with reference to FIG. 4, a magnesium fluorosilicate crystal is generated.

A lid in which 5400 g of the MgSiF ₆ .6H ₂ O fine particle dispersion (7%) obtained by executing Step S308 is filled in a reaction vessel (made by PFA), and an N ₂ gas introduction port and an exhaust port are attached. Did. The MgSiF ₆ .6H ₂ O fine particle dispersion was dried using a drier while flowing N ₂ gas (flow rate: ₂ L / min) into the reaction vessel (manufactured by PFA) (drying temperature 80 ° C., drying time 72 hours). After drying, about 371 g of white powder (magnesium fluorosilicate crystal: MgSiF ₆ .6H ₂ O) was obtained.

[Formation of magnesium fluoride crystals]
By performing step S312 described with reference to FIG. 4, a magnesium fluoride crystal is generated.

Of the white powder (magnesium fluorosilicate crystal) obtained by executing step S310, 370 g was filled in an alumina crucible, and the white powder was heat-treated in an N ₂ gas atmosphere using an electric furnace. The heat treatment temperature is 400 ° C. and the heat treatment time is 8 hours. After the heat treatment, the temperature was lowered to room temperature (20 to 23 ° C.) in an N ₂ gas atmosphere, and 71.8 g of white powder could be taken out from the alumina crucible. When the powder was analyzed by XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgF ₂ (magnesium fluoride crystal). Thus, the yield of MgF ₂ (magnesium fluoride crystal) that could be generated from MgSiF ₆ .6H ₂ O was 86%.

[Slurry production of magnesium fluoride fine particles]
By executing step S314 described with reference to FIG. 4, a slurry of magnesium fluoride fine particles is generated.

The white powder (MgF ₂ : 30 g) obtained by executing Step S312 is added to isopropanol (470 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and sufficiently stirred, and the MgF ₂ dispersion (6%: 500 g) is added. Obtained. The MgF ₂ dispersion was dispersed with a bead mill (manufactured by Shinmaru Enter Co., Ltd.) to obtain a dispersion. While performing dispersion treatment using zirconia beads (Nikkato Co., Ltd.), the particle size distribution of MgF ₂ (magnesium fluoride fine particles) in the dispersion was measured using a particle size distribution analyzer (Nikkiso Co., Ltd .: Microtrac UPA-UZ152). It was measured. As a result of dispersion treatment until the average particle diameter (volume conversion, d50) of MgF ₂ became 30 nm or less, 375 g of a fine particle dispersion solution (magnesium fluoride fine particle slurry: 6%) of MgF ₂ was obtained.

[Manufacture of magnesium fluoride particles 100]
Magnesium fluoride particles 100 are manufactured by executing step S316 described with reference to FIG.

  The magnesium fluoride fine particle dispersion (magnesium fluoride fine particle slurry: 370 g) obtained by executing step S314 is evaporated to dryness at 50 ° C. or higher and 110 ° C. or lower, and then maintained at 200 ° C. or higher and 400 ° C. or lower. As a result, magnesium fluoride particles 100 (about 21 g) were obtained.

[Production of Magnesium Fluoride Particle Dispersion 200]
By executing step S502 described with reference to FIG. 6, the magnesium fluoride particle dispersion 200 is manufactured.

Magnesium fluoride particles 100 (powder 20 g) obtained by executing Step S316 are added to isopropanol (380 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and sufficiently stirred, and magnesium fluoride particle dispersion 200 (5% : 400 g). When the refractive index of the magnesium fluoride particles 100 with respect to light having a wavelength of 550 nm was measured, the refractive index was 1.34. Since the refractive index of single crystal MgF ₂ with respect to light having a wavelength of 550 nm was 1.38, it was confirmed that the magnesium fluoride particles 100 had pores 130.

[Example 3]
[Formation of magnesium fluorosilicate particles]
By executing steps S302 to S306 described with reference to FIG. 4, magnesium fluorosilicate particles are generated.

H ₂ SiF ₆ aqueous solution (40%: 720.5g) weighed to put in a reaction vessel (made PFA), and after the liquid temperature at 80 ° C. by a water bath, MgCl ₂ with stirring maintaining the liquid temperature to 80 ° C. 6H ₂ O (205 g: manufactured by Kanto Chemical Co., Inc.) was continuously added in small portions over about 30 minutes to obtain a reaction solution. Thereafter, the reaction solution was aged for 1 hour while keeping the temperature of the reaction solution at 80 ° C.

  Remove the reaction vessel from the water bath and leave it for about 2 hours. When the reaction solution reaches room temperature (20-23 ° C.), add isopropanol (925 g: reagent grade product manufactured by Wako Pure Chemical Industries, Ltd.) Stirring to obtain a stirred reaction solution. The stirred reaction liquid was subjected to suction filtration with a membrane filter (pore size 5 μm: manufactured by Millipore) for about 2 hours, and a magnesium silicofluoride particle paste (678.2 g) was obtained as a filtration residue.

The magnesium silicofluoride particle paste was placed in a reaction vessel (manufactured by PFA) and dried using a drier while flowing high purity N ₂ gas (flow rate 5 L / min) into the reaction vessel (manufactured by PFA) (drying temperature 60 ° C, drying time 96 hr). After drying, 210 g of white powder was obtained. When the white powder was analyzed by XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgSiF ₆ .6H ₂ O. Further, as a result of TG measurement of the powder using a thermobalance (EXSTAR6000 TG / DTA6300 manufactured by Seiko), it was confirmed that the powder was a 6H ₂ O salt. The yield of MgSiF ₆ · 6H ₂ O was 76.5%.

[Slurry production of magnesium fluorosilicate fine particles]
By executing step S308 described with reference to FIG. 4, a slurry of magnesium fluorosilicate fine particles is generated.

The white powder (MgSiF ₆ .6H ₂ O: 200 g) obtained by executing Step S306 is added to isopropanol (3133 g: reagent special grade manufactured by Wako Pure Chemical Industries, Ltd.) and stirred sufficiently to obtain a solution (about 6 %). The powder was pulverized with a bead mill (manufactured by Shinmaru Enter Co., Ltd.), so that the average particle size of the powder was 20 nm or less. The powder was pulverized several times to produce a MgSiF ₆ .6H ₂ O fine particle dispersion (magnesium silicofluoride fine particle slurry). The weight of the MgSiF ₆ · 6H ₂ O fine particle dispersion was about 3100 g, and the concentration of the MgSiF ₆ · 6H ₂ O fine particle dispersion was about 6%.

[Formation of magnesium silicofluoride crystals]
By executing step S310 described with reference to FIG. 4, a magnesium fluorosilicate crystal is generated.

Of the MgSiF ₆ .6H ₂ O fine particle dispersion (about 6%) obtained by executing Step S308, 3050 g was filled in a reaction vessel (manufactured by PFA), and an N ₂ gas introduction port and an exhaust port were attached. Covered. The MgSiF ₆ .6H ₂ O fine particle dispersion was dried using a dryer (flowing temperature: 80 ° C., drying time: 48 hours) while N ₂ gas was flowed into the reaction vessel (manufactured by PFA) (flow rate: ₂ L / min). After drying, about 181 g of white powder (magnesium fluorosilicate crystal: MgSiF ₆ .6H ₂ O) was obtained.

[Formation of magnesium fluoride crystals]
By performing step S312 described with reference to FIG. 4, a magnesium fluoride crystal is generated.

Of the white powder (magnesium fluorosilicate crystal) obtained by executing Step S310, 180 g was filled in an alumina crucible, and the white powder was heat-treated in an N ₂ gas atmosphere using an electric furnace. The heat treatment temperature is 600 ° C., and the heat treatment time is 3 hours. After the heat treatment, the temperature was lowered to room temperature (20 to 23 ° C.) in an N ₂ gas atmosphere, and then 34 g of white powder could be taken out from the alumina crucible. When the powder was analyzed by XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgF ₂ (magnesium fluoride crystal). Accordingly, the yield of MgF ₂ (magnesium fluoride crystal) that could be generated from MgSiF ₆ .6H ₂ O was 83%.

[Slurry production of magnesium fluoride fine particles]
By executing step S314 described with reference to FIG. 4, a slurry of magnesium fluoride fine particles is generated.

The white powder (MgF ₂ : 30 g) obtained by executing Step S312 is added to isopropanol (470 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and sufficiently stirred, and the MgF ₂ dispersion (6%: 500 g) is added. Obtained. The MgF ₂ dispersion was dispersed with a bead mill (manufactured by Shinmaru Enter Co., Ltd.) to obtain a dispersion. While performing dispersion treatment using zirconia beads (Nikkato Co., Ltd.), the particle size distribution of MgF ₂ (magnesium fluoride fine particles) in the dispersion was measured using a particle size distribution analyzer (Nikkiso Co., Ltd .: Microtrac UPA-UZ152). It was measured. As a result of dispersion treatment until the average particle diameter (volume conversion, d50) of MgF ₂ became 30 nm or less, 364 g of a fine particle dispersion solution (magnesium fluoride fine particle slurry: 6%) of MgF ₂ was obtained.

[Manufacture of magnesium fluoride particles 100]
Magnesium fluoride particles 100 are manufactured by executing step S316 described with reference to FIG.

  The magnesium fluoride fine particle dispersion (magnesium fluoride fine particle slurry: about 364 g) obtained by executing Step S314 is evaporated to dryness at 50 ° C. or higher and 110 ° C. or lower, and then maintained at 200 ° C. or higher and 400 ° C. or lower. Heat treatment was performed to obtain magnesium fluoride particles 100 (about 21 g).

[Production of Magnesium Fluoride Particle Dispersion 200]
By executing step S502 described with reference to FIG. 6, the magnesium fluoride particle dispersion 200 is manufactured.

Magnesium fluoride particles 100 (powder 20 g) obtained by executing Step S316 are added to isopropanol (380 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and sufficiently stirred, and magnesium fluoride particle dispersion 200 (5% : 400 g). When the refractive index of the magnesium fluoride particles 100 with respect to light having a wavelength of 550 nm was measured, the refractive index was 1.35. Since the refractive index of single crystal MgF ₂ with respect to light having a wavelength of 550 nm was 1.38, it was confirmed that the magnesium fluoride particles 100 had pores 130.

[Example 4]
[Formation of magnesium fluorosilicate particles]
By executing steps S302 to S306 described with reference to FIG. 4, magnesium fluorosilicate particles are generated.

H ₂ SiF ₆ aqueous solution (40%: 1000 g) was weighed and placed in a reaction vessel (made by PFA), and the liquid temperature was raised to 80 ° C. with a water bath. ₂ (150 g: manufactured by Kanto Chemical Co., Inc.) was continuously added in small portions over about 30 minutes to obtain a reaction solution. Thereafter, the reaction solution was aged for 1 hour while keeping the temperature of the reaction solution at 80 ° C.

  Remove the reaction vessel from the water bath, leave it for about 2 hours, and when the reaction solution reaches room temperature (20-23 ° C.), add isopropanol (950 g: reagent special grade manufactured by Wako Pure Chemical Industries, Ltd.) Stirring to obtain a stirred reaction solution. The stirred reaction solution was subjected to suction filtration with a membrane filter (pore size 5 μm: manufactured by Millipore) for about 2 hours to obtain a magnesium silicofluoride particle paste as a filtration residue.

The magnesium silicofluoride particle paste was placed in a reaction vessel (made by PFA) and dried using a drier (flowing temperature 70) while flowing high purity N ₂ gas (flow rate 5 L / min) into the reaction vessel (made by PFA). ° C, drying time 96 hr). After drying, 515 g of white powder was obtained. When the white powder was analyzed by XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgSiF ₆ .6H ₂ O. Further, as a result of TG measurement of the powder using a thermobalance (EXSTAR6000 TG / DTA6300 manufactured by Seiko), it was confirmed that the powder was a 6H ₂ O salt. The yield of MgSiF ₆ .6H ₂ O was 73%.

[Slurry production of magnesium fluorosilicate fine particles]
By executing step S308 described with reference to FIG. 4, a slurry of magnesium fluorosilicate fine particles is generated.

The white powder (MgSiF ₆ .6H ₂ O: 300 g) obtained by executing Step S306 is added to isopropanol (4315 g: reagent special grade manufactured by Wako Pure Chemical Industries, Ltd.) and stirred sufficiently to obtain a solution (about 6 .5%). The powder was pulverized by a bead mill (manufactured by Shinmaru Enter Co., Ltd.), and the average particle size of the powder was adjusted to 20 nm or less. The powder was pulverized several times to produce a MgSiF ₆ .6H ₂ O fine particle dispersion (magnesium silicofluoride fine particle slurry). The weight of the MgSiF ₆ · 6H ₂ O fine particle dispersion was about 4200 g, and the concentration of the MgSiF ₆ · 6H ₂ O fine particle dispersion was about 6.5%.

  By executing step S310 described with reference to FIG. 4, a magnesium fluorosilicate crystal is generated.

Of the MgSiF ₆ .6H ₂ O fine particle dispersion (about 6.5%) obtained by executing step S308, 4000 g is filled in a reaction vessel (made of PFA), and an N ₂ gas inlet, an exhaust port, The lid was attached. The MgSiF ₆ .6H ₂ O fine particle dispersion was dried using a dryer (flowing temperature: 80 ° C., drying time: 48 hours) while N ₂ gas was flowed into the reaction vessel (manufactured by PFA) (flow rate: ₂ L / min). After drying, about 255 g of white powder (magnesium fluorosilicate crystal: MgSiF ₆ .6H ₂ O) was obtained.

[Formation of magnesium fluoride crystals]
By performing step S312 described with reference to FIG. 4, a magnesium fluoride crystal is generated.

Of the white powder (magnesium fluorosilicate crystal) obtained by executing Step S310, 250 g was filled in an alumina crucible, and the white powder was heat-treated in an N ₂ gas atmosphere using an electric furnace. The heat treatment temperature is 600 ° C., and the heat treatment time is 3 hours. After the heat treatment, the temperature was lowered to room temperature (20 to 23 ° C.) in an N ₂ gas atmosphere, and 48.2 g of white powder could be taken out from the alumina crucible. When the powder was analyzed by XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgF ₂ (magnesium fluoride crystal). From this, the yield of MgF ₂ (magnesium fluoride crystal) that could be produced from MgSiF ₆ .6H ₂ O (250 g) was 85%.

[Slurry production of magnesium fluoride fine particles]
By executing step S314 described with reference to FIG. 4, a slurry of magnesium fluoride fine particles is generated.

The white powder (MgF ₂ : 35 g) obtained by executing Step S 312 is added to isopropanol (465 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and sufficiently stirred, and the MgF ₂ dispersion (7%: 500 g) is added. Obtained. The MgF ₂ dispersion was dispersed with a bead mill (manufactured by Shinmaru Enter Co., Ltd.) to obtain a dispersion. While performing dispersion treatment using zirconia beads (Nikkato Co., Ltd.), the particle size distribution of MgF ₂ (magnesium fluoride fine particles) in the dispersion was measured using a particle size distribution analyzer (Nikkiso Co., Ltd .: Microtrac UPA-UZ152). It was measured. As a result of dispersion treatment until the average particle diameter (volume conversion, d50) of MgF ₂ became 30 nm or less, 372 g of a fine particle dispersion solution (magnesium fluoride fine particle slurry: 7%) of MgF ₂ was obtained.

[Manufacture of magnesium fluoride particles 100]
Magnesium fluoride particles 100 are manufactured by executing step S316 described with reference to FIG.

  The magnesium fluoride fine particle dispersion (magnesium fluoride fine particle slurry: about 372 g) obtained by executing step S314 is evaporated to dryness at 50 ° C. or higher and 110 ° C. or lower, and then maintained at 200 ° C. or higher and 400 ° C. or lower. Heat treatment was performed to obtain magnesium fluoride particles 100 (about 25 g).

[Production of Magnesium Fluoride Particle Dispersion 200]
By executing step S502 described with reference to FIG. 6, the magnesium fluoride particle dispersion 200 is manufactured.

Magnesium fluoride particles 100 (powder 20 g) obtained by executing Step S316 are added to isopropanol (380 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and sufficiently stirred, and magnesium fluoride particle dispersion 200 (5% : 400 g). When the refractive index of the magnesium fluoride particles 100 with respect to light having a wavelength of 550 nm was measured, the refractive index was 1.34. Since the refractive index of single crystal MgF ₂ with respect to light having a wavelength of 550 nm was 1.38, it was confirmed that the magnesium fluoride particles 100 had pores 130.

[Comparative Example 1]
[Production of MgF ₂ ]
Ultrapure water (780 g) was weighed and placed in a reaction vessel (manufactured by PFA), and an aqueous HF solution (50%: 200 g) was added while stirring with a stirrer using a magnetic stirrer to obtain a reaction solution. While maintaining the temperature of the reaction solution at a constant temperature of 50 ° C. with a water bath, MgCO ₃ (200 g: manufactured by Kamijima Co., Ltd.) was continuously added in small portions over about 30 minutes to obtain a reaction solution. Thereafter, the reaction solution was aged for 1 hour while keeping the temperature of the reaction solution at 80 ° C. Since the reaction proceeds promptly, it may become a gel in the middle and stirring may be stopped.

Remove the reaction vessel from the water bath and leave it for about 2 hours. When the reaction solution reaches room temperature (20-23 ° C.), add isopropanol (1000 g: reagent grade product manufactured by Wako Pure Chemical Industries, Ltd.) Stir. The reaction solution was put into a reaction vessel (manufactured by PFA) and dried using a drier while flowing high purity N ₂ gas (flow rate 5 L / min) into the reaction vessel (manufactured by PFA) (drying temperature 110 ° C., drying time). 96 hr). After drying, about 137 g of white powder was obtained.

The obtained white powder (about 137 g) was filled in an alumina crucible, and the white powder was heat-treated in an N ₂ gas atmosphere using an electric furnace. The heat treatment temperature is 600 ° C., and the heat treatment time is 3 hours. After the heat treatment, the temperature was lowered to room temperature (20 to 23 ° C.) in an N ₂ gas atmosphere, and 134.8 g of white powder could be taken out from the alumina crucible. When the white powder was analyzed with XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgF ₂ . The yield of MgF ₂ produced from MgCO ₃ (200 g) was about 91%.

[Production of MgF ₂ fine particle dispersion]
The obtained white powder (MgF ₂ : 42 g) was added to isopropanol (558 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and stirred sufficiently to obtain a MgF ₂ dispersion (7%: 600 g). The MgF ₂ dispersion was dispersed with a bead mill (manufactured by Shinmaru Enter Co., Ltd.) to obtain a dispersion. While performing dispersion treatment using zirconia beads (Nikkato), the particle size distribution of MgF _{2 in} the dispersion was measured using a particle size distribution analyzer (Nikkiso Co., Ltd .: Microtrac UPA-UZ152). As a result of dispersion treatment until the average particle diameter (volume conversion, d50) of MgF ₂ became 30 nm or less, 478 g of a fine particle dispersion solution (7%) of MgF ₂ was obtained.

[Production of fine powder of MgF ₂ ]
The obtained MgF ₂ fine particle dispersion (about 478 g) was evaporated to dryness at 50 ° C. or higher and 110 ° C. or lower and then heat-treated at 200 ° C. or higher and 400 ° C. or lower to obtain MgF ₂ fine particles (about 26 g). .

[Production of MgF ₂ fine particle dispersion]
The obtained MgF ₂ fine particles (about 26 g) were added to isopropanol (400 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and stirred sufficiently to obtain MgF ₂ particle dispersion 200 (7%: 430 g). When the refractive index of the MgF ₂ fine particles with respect to light having a wavelength of 550 nm was measured, it was the same as that of the single crystal MgF ₂ and the refractive index was 1.38.

[Comparative Example 2]
[Production of MgF ₂ ]
Ultrapure water (755 g) was weighed and placed in a reaction vessel (manufactured by PFA), and an aqueous HF solution (50%: 90 g) was added while stirring with a stirrer using a magnetic stirrer to obtain a reaction solution. While keeping the temperature of the reaction solution at a constant temperature of 50 ° C. with a water bath, MgCl ₂ .6H ₂ O (200 g: manufactured by Kanto Kagaku) is continuously added in small portions over about 30 minutes to obtain a reaction solution. It was. Thereafter, the reaction solution was aged for 1 hour while keeping the temperature of the reaction solution at 80 ° C. Since the reaction proceeds promptly, it may become a gel in the middle and stirring may be stopped.

Remove the reaction vessel from the water bath and leave it for about 2 hours. When the reaction solution reaches room temperature (20-23 ° C.), add isopropanol (1000 g: reagent grade product manufactured by Wako Pure Chemical Industries, Ltd.) Stir. The reaction solution was placed in a reaction vessel (manufactured by PFA) and dried using a dryer while flowing high purity N ₂ gas (flow rate ₂ L / min) into the reaction vessel (manufactured by PFA) (drying temperature 110 ° C., drying time). 96 hr). After drying, about 58 g of white powder was obtained.

The obtained white powder (about 58 g) was filled in an alumina crucible, and the white powder was heat-treated in an N ₂ gas atmosphere using an electric furnace. The heat treatment temperature is 600 ° C., and the heat treatment time is 3 hours. After the heat treatment, the temperature was lowered to room temperature (20 to 23 ° C.) in an N ₂ gas atmosphere, and then 55.1 g of white powder could be taken out from the alumina crucible. When the white powder was analyzed with XRD (RINT-Ultima III, manufactured by Rigaku Corporation), it was confirmed that the powder was MgF ₂ . The yield of MgF ₂ produced from MgCl ₂ .6H ₂ O (200 g) was about 90%.

[Production of MgF ₂ fine particle dispersion]
The obtained white powder (MgF ₂ : 35 g) was added to isopropanol (465 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and stirred sufficiently to obtain a MgF ₂ dispersion (7%: 500 g). The MgF ₂ dispersion was dispersed with a bead mill (manufactured by Shinmaru Enter Co., Ltd.) to obtain a dispersion. While performing dispersion treatment using zirconia beads (Nikkato), the particle size distribution of MgF _{2 in} the dispersion was measured using a particle size distribution analyzer (Nikkiso Co., Ltd .: Microtrac UPA-UZ152). As a result of dispersion treatment until the average particle diameter of MgF ₂ (volume conversion, d50) was 30 nm or less, 370 g of a fine particle dispersion solution (7%) of MgF ₂ was obtained.

[Production of fine powder of MgF ₂ ]
The obtained MgF ₂ fine particle dispersion (about 370 g) was evaporated to dryness at 50 ° C. or higher and 110 ° C. or lower and then heat-treated at 200 ° C. or higher and 400 ° C. or lower to obtain MgF ₂ fine particles (about 22 g). .

[Production of MgF ₂ fine particle dispersion]
The obtained MgF ₂ fine particles (20 g) were added to isopropanol (315 g: reagent grade product manufactured by Yasu Pharmaceutical Co., Ltd.) and stirred sufficiently to obtain MgF ₂ particle dispersion 200 (6%: 335 g). When the refractive index of the MgF ₂ fine particles with respect to light having a wavelength of 550 nm was measured, it was the same as that of the single crystal MgF ₂ and the refractive index was 1.38.

As described above, the magnesium fluoride particles 100 and the magnesium fluoride particle dispersion 200 were manufactured by executing the examples 1 to 4. Furthermore, by executing Comparative Example 1 and Comparative Example 2, MgF ₂ fine particles and MgF ₂ fine particle dispersions were produced.

[Example: Production of substrate with low refractive index layer]
Below, the base material 400 with the low refractive index layer containing the magnesium fluoride particle 100 manufactured by performing Example 1- Example 4, and also MgF manufactured by performing the comparative example 1 and the comparative example 2 Examples for the production of a substrate with a low refractive index layer containing _two fine particles will be described.

  First, a PET substrate (PET film) on which a hard coat layer is laminated is produced. A paint (Toyo Ink Manufacturing Co., Ltd. TYS63) containing antimony pentoxide fine particles (27% by mass) and urethane acrylate on one easy-adhesive surface of an optically-adhesive polyester film (Toray Lumirror (registered trademark) U34: 100 μm thick) : Refractive index 1.63 of coating film, solid content concentration 40% by mass) was applied with a bar coater. After drying at 90 ° C., ultraviolet rays (400 mJ / cm 2) were irradiated to cure the paint, thereby forming a hard coat layer.

Next, a low refractive index layer-attached base material (antireflection film) is manufactured by laminating a low refractive index layer on a hard coat layer on a PET substrate (PET film). A paint prepared by adding 3 parts of polyester-modified hydroxyl group-containing polydimethylsiloxane (Big Chemie: BYK370) to the low refractive index paint (solid content: 100 parts) was applied onto the hard coat layer with a bar coater. The paint applied on the hard coat layer was dried at 130 ° C. and then cured by irradiating with ultraviolet rays of 400 mJ / cm ² , and a low refractive index layer (thickness: about 100 nm) was laminated on the hard coat layer.

Production of a substrate with a low refractive index layer (antireflective film) in which a hard coat layer and a low refractive index layer are laminated on a PET film by executing an example of the production of a substrate with a low refractive index layer did. Note that the refractive index, haze value, total light transmittance and minimum reflectance of the low refractive index layer containing magnesium fluoride particles 100 and the low refractive index layer containing MgF ₂ fine particles are measured, and the low refractive index layer is scratch-resistant. The evaluation method of sex is as follows.

[Measurement of refractive index of low refractive index layer]
A paint was prepared by adding polyester-modified hydroxyl group-containing polydimethylsiloxane to the composition for forming a low refractive index layer. The prepared paint was applied onto the mirror polished surface of the silicon wafer by a spin coater, dried at 130 ° C. and cured. The refractive index of the low refractive index layer cured using a spectroscopic ellipsometer (UVISE M200-FUV-AGMS manufactured by HORIBA JOBIN YVON) at a temperature of 23 ° C. was measured.

[Haze measurement, total light transmittance measurement and minimum reflectance measurement]
The haze value of the low-refractive index layer, the total light transmittance of the low-refractive index layer, and the minimum reflectance of the low-refractive index layer are determined according to JIS K 7136, an ultraviolet-visible near-infrared spectrophotometer (V670; JASCO Corporation) It measured using.

  The haze value is a ratio of diffuse transmitted light to total transmitted light when the film is irradiated with visible light. The smaller the haze value, the better the transparency of the film. The haze value is desirably 1.5% or less, and the total light transmittance is desirably 90% or more. Regarding the minimum reflectance, an absolute reflection spectrum in a wavelength region of 300 nm to 800 nm was measured at an incident angle of 5 degrees, and a reflectance at wavelengths of 400 nm and 700 nm and a minimum reflectance in a region of 400 nm to 700 nm were measured. When the measured reflection spectrum has undulations, the reflectance at wavelengths of 400 nm and 700 nm is calculated based on a curve formed by connecting intermediate points between undulation peaks (maximum points) and valleys (minimum points). The minimum reflectance in the region of 400 nm to 700 nm was determined. The lower the minimum reflectance, the higher the antireflective function of the low refractive index layer and the better.

[Abrasion resistance]
Regarding the scratch resistance of the low refractive index layer, steel wool (SW) hardness evaluation was performed. A load (250 g) was applied to steel wool (# 0000), and the antireflective surface of the low refractive index layer was subjected to 10 reciprocating frictions at a stroke width of 10 cm and a speed of 30 mm / sec. The surface was visually observed, and how the scratches were made was evaluated in three stages (Class A: 0 to 10 scratches, Class B: 11 to 20 scratches, Class C: 20 or more scratches).

  FIG. 10 is a table showing measurement results of magnesium fluoride particles, a low refractive index layer, and a substrate with a low refractive index layer produced by executing the examples and comparative examples.

  The refractive index of the magnesium fluoride particles was 1.38 in Comparative Examples 1 to 2 of the prior art, but was 1.34 to 1.35 in Examples 1 to 4 of the present invention. The magnesium fluoride particles of the examples according to the present invention had lower refraction than the prior art magnesium fluoride particles.

The specific surface area of the magnesium fluoride particles, was the comparative example 1 to Comparative Example 2, 119m ² / g~134m ² / g in the prior art, Examples 1 to 4, 174m ² / g to the present invention It was 193 m ² / g. The specific surface area of the magnesium fluoride particles of the examples according to the present invention was larger than that of the prior art magnesium fluoride particles.

  The refractive index of the low refractive index layer was 1.39 to 1.40 in Comparative Examples 1 to 2 of the prior art, but 1.35 to 1.36 in Examples 1 to 4 of the present invention. Met. The low refractive index layer of the example according to the present invention was lower in refraction than the low refractive index layer of the prior art.

  The total light transmittance of the low refractive index layer was 93.23% to 94.56% in Comparative Examples 1 to 2 of the prior art, but 95.49 in Examples 1 to 4 of the present invention. % To 96.01%. The total light transmittance of the low refractive index layer of the example according to the present invention was higher than the total light transmittance of the low refractive index layer of the prior art.

  The haze value of the low refractive index layer was 1.62% to 1.65% in Comparative Examples 1 to 2 of the prior art, but 1.45% to Example 1 to Example 4 in the present invention. 1.50%. The haze value of the low refractive index layer of the example according to the present invention was smaller than the haze value of the low refractive index layer of the prior art.

  The minimum reflectance of the low refractive index layer was 0.62% to 0.78% in Comparative Examples 1 to 2 of the prior art, but 0.26% in Examples 1 to 4 of the present invention. It was ˜0.40%. The minimum reflectance of the low refractive index layer of the example according to the present invention was smaller than the minimum reflectance of the low refractive index layer of the prior art.

  Regarding the evaluation of the scratch resistance of the low refractive index layer, it was class A in Comparative Examples 1 to 2 of the prior art, but it was also Class A in Examples 1 to 4 of the present invention. The evaluation of the scratch resistance of the low refractive index layer of the example according to the present invention was equivalent to the evaluation of the scratch resistance of the low refractive index layer of the prior art.

  According to the present invention, for example, reflection of external light on the display surface can be prevented, and the present invention can be used for a flat panel display such as a liquid crystal display (LCD) or a plasma display panel (PDP).

A Container 100 Magnesium fluoride particles 110 Fine particles 120 Concavities and convexities 130 Pore 130a Intragranular open pores 130b Intragranular closed pores 130c Grain boundary void-like open pores 130d Grain boundary void-like closed pores 200 Fluorine magnesium particle dispersion 210 Dispersion medium 300 Composition for forming low refractive index layer 310 Binder 400 Substrate with low refractive index layer 410 Low refractive index layer 420 Hard coat layer 430 Resin substrate

Claims (18)

A magnesium fluoride particles containing at least one magnesium fluoride microparticles, each of said at least one magnesium fluoride microparticles, have a pore carrying the object carrier,
The magnesium fluoride fine particles have an average particle size of 1 nm to 100 nm,
The specific surface area by the BET method of the magnesium fluoride fine particles is in the range of 150 m ² / g to 300 m ² / g,
The refractive index of the magnesium fluoride fine particles is in the range of 1.20 or more and 1.40 or less,
The fine pores as the support,
air,
A gas containing an inert gas,
A liquid containing an organic solution,
A liquid, solvent or gas used in the process of producing the at least one magnesium fluoride particulate, and
A material having a refractive index lower than that of the at least one magnesium fluoride fine particle;
Magnesium fluoride particles carrying at least one selected from the group consisting of: The at least one magnesium fluoride fine particle is a plurality of fine particles,
2. The magnesium fluoride particles according to claim 1, wherein among the plurality of fine particles, there are intergranular void-like pores, which are gaps for supporting the support, between adjacent fine particles. The fine pores are fine pores that are open in the state of being opened on the surface of the magnesium fluoride fine particles, and fine particles that are in the state of being blocked from the surface of the magnesium fluoride fine particles inside the magnesium fluoride fine particles. The magnesium fluoride particle according to claim 1 or 2 , wherein the magnesium fluoride particle is at least one of the inner closed pores. The grain boundary void-like pores, and grain boundary void-like open pores present at the open state, at least one of a grain boundary void-like閉細pores present in closed state, to claim 2 Magnesium fluoride particles as described. The average particle diameter of the magnesium fluoride fine particles are 1 nm to 50 nm, magnesium fluoride particles according to one of claims 1 to 4. Magnesium fluoride particles according to one of claims 1 to 5,
A magnesium fluoride particle dispersion comprising: a dispersion medium for dispersing the magnesium fluoride particles. The magnesium fluoride particle dispersion according to claim 6 , wherein the dispersion medium includes a dispersant that promotes dispersion of the magnesium fluoride particles. Magnesium fluoride particles according to one of claims 1 to 5,
A composition for forming a low refractive index layer, comprising: a layer forming material in which the magnesium fluoride particles are dispersed. A resin substrate;
A hard coat layer formed on the resin substrate;
A substrate with a low refractive index layer, comprising a low refractive index layer formed on the hard coat layer,
The said low refractive index layer is a base material with a low refractive index layer comprised from the composition for low refractive index layer formation of Claim 8 . A method for producing magnesium fluoride particles, comprising producing magnesium fluoride particles containing at least one magnesium fluoride fine particle,
A preparation process for preparing magnesium fluorosilicate crystals;
A crystal production step of discharging a gas from the magnesium silicofluoride crystal by heat-treating the magnesium silicofluoride crystal, and producing a magnesium fluoride crystal having pores for supporting a support;
A fine particle production step of producing magnesium fluoride fine particles having the pores from the magnesium fluoride crystal. The at least one magnesium fluoride fine particle is a plurality of fine particles,
The crystal generation step includes
Including an aggregating step of aggregating the adjacent fine particles so that intergranular void-shaped pores are formed between the adjacent fine particles among the plurality of fine particles,
11. The method for producing magnesium fluoride particles according to claim 10 , wherein the grain boundary void-like pores are gaps that carry the support. The crystal generation step includes
A step of forming fine pores in the fine particles existing in the state of being opened on the surface of the magnesium fluoride fine particles;
Comprising at least one of the steps above the inside surface of the magnesium fluoride fine particles of magnesium fluoride fine particles forming the fine particles in閉細pores present in a state of closing, in claim 10 or claim 11 The manufacturing method of the magnesium fluoride particle of description. The aggregation step includes
Forming a grain boundary void-like open pore that exists in an open state; and
The method for producing magnesium fluoride particles according to claim 11 , comprising at least one of a step of forming closed pores having grain boundary voids existing in a closed state. The preparation step includes
Producing a magnesium silicofluoride particle aggregate slurry from a mixture of a magnesium salt and a solution containing silicofluoride ions;
Producing a magnesium silicofluoride particle paste from the magnesium silicofluoride particle aggregate slurry;
Producing magnesium silicofluoride particles from the paste of magnesium silicofluoride particles;
Crushing the magnesium silicofluoride particles to produce a slurry of magnesium silicofluoride particles;
Method for producing a magnesium fluoride particles according to one of the said from a slurry of magnesium fluorosilicate particles comprising a step of generating a crystalline magnesium fluorosilicate, claims 10 to claim 13. Preparing the magnesium fluoride particles according to one of claims 1 to 5 ,
And a dispersion step of dispersing the magnesium fluoride particles in a dispersion medium. The said dispersion medium is a manufacturing method of the magnesium fluoride particle dispersion liquid of Claim 15 containing the dispersing agent which accelerates | stimulates dispersion | distribution of the said magnesium fluoride particle. Preparing the magnesium fluoride particles according to one of claims 1 to 5 ,
And a dispersion step of dispersing the magnesium fluoride particles in a layer forming material. A step of preparing a resin substrate;
Forming a hard coat layer on the resin substrate;
Forming a low refractive index layer on the hard coat layer, and a method for producing a substrate with a low refractive index layer,
The said low-refractive-index layer is a manufacturing method of the base material with a low-refractive-index layer comprised from the composition for low-refractive-index layer formation of Claim 8 .

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